WO2016125645A1 - Glass-fiber thermal-insulation sound absorbing body and usage thereof - Google Patents

Abstract

A glass-fiber thermal-insulation sound absorbing body (1) according to the present invention is provided with a flexible part (2) and a high-rigidity part (3) that are molded by intertwining a plurality of glass fibers and that are stacked on each other; the density of the flexible part (2) is greater than 80 kg/m³ and equal to or less than 100 kg/m³; and the density of the high-rigidity part (3) ranges from 120 kg/m³ to 300 kg/m³, and the bending elastic modulus thereof ranges from 150 MPa to 500 MPa.

Description

Glass fiber insulation sound absorber and method of using the same

The present invention relates to a heat insulating sound absorber made of glass fiber, and more particularly to a glass fiber heat insulating sound absorber used for sound absorption in an automobile engine room and a method of using the same.

In the engine room of an automobile, a glass fiber heat insulating sound absorber is used for the purpose of reducing noise and heat insulation generated from the engine section. This glass fiber heat-absorbing sound absorber is formed by press-heating and molding a mat-like glass fiber assembly to which an uncured thermosetting resin is adhered.

A general glass fiber heat-absorbing sound absorber is a molded body having a density of 100 kg / m ³ and a thickness of 30 mm or less, so that the rigidity is insufficient. For this reason, from the viewpoint of preventing deformation during assembly of the engine compartment and improving rigidity, the glass fiber heat-absorbing sound absorber is attached to a metal molded article or thermoplastic resin molded article having the same shape as that between the engine compartment and the vehicle compartment. It is used by attaching to the periphery of the engine part and the lower part.

In addition, when mounted on the lower surface of the engine room, the metal molded product or the thermoplastic resin molded product is used to prevent damage to engine parts caused by jumping (chipping) of pebbles or the like while the vehicle is running.

In recent years, automobiles have been required to reduce the weight of each part from the viewpoint of energy saving, etc., and it is hoped that the sound absorbing body will also be reduced in weight by eliminating the metal molded product or thermoplastic resin molded product. It is rare.

In order to deal with such a problem, in Patent Document 1, a bulky soundproof portion having a density of substantially 8.0 to 80.0 kg / m ³ is integrated with the soundproof portion along at least one face thereof. An insulator-type liner comprising a fibrous material pad having a relatively dense skin layer provided and a crimped edge having a thickness of about 0.5 to 3.0 mm, the skin layer having a thickness An insulator type liner is disclosed, characterized in that the length is substantially 0.25 to 10.0 mm and the density is substantially 32.0 to 1600.0 kg / m ³ .

Japanese Patent No. 4129427

However, the space inside the engine compartment of an automobile, particularly the space around the engine is narrow, and the thickness of the glass fiber heat-absorbing sound absorber is limited. Therefore, it is necessary to increase the sound absorption in a limited thickness. The sound absorptivity with respect to noise of 1000 Hz or more required for automobiles or the like is greatly influenced by the density of the glass fiber heat-absorbing sound absorber. If the density of the glass fiber heat-absorbing sound absorber is too low, sound is easily transmitted, and if the density is too high, the sound is reflected. When the sound is reflected, the sound is amplified from a few places where the sound absorber is not installed, and the phenomenon of leaking to the outside occurs. For this reason, the setting of the thickness and density of the glass fiber heat-absorbing sound absorber is important.

In addition, in a sound absorber made of glass fiber, a resonance phenomenon (coincidence effect) occurs in the vicinity of 3000 Hz to 4000 Hz due to the elastic modulus of the glass fiber (refer to part A in FIG. 4), and the sound absorption coefficient is lowered by the normal incidence method. End up. Therefore, there is also a demand for sound absorption measures in this frequency band.

Further, as described in Patent Document 1, when the density of the skin layer is 1000 kg / m ³ or more, the density becomes the same as or equal to or higher than that of a thermoplastic resin molded product, and the present invention is intended. It will not follow the weight reduction.

The present invention is based on the above prior art, and can achieve weight reduction while having chipping-proof performance, and further prevents a decrease in sound absorption coefficient due to a resonance phenomenon in the vicinity of 3000 Hz to 4000 Hz and its use. It aims to provide a method.

In order to achieve the above object, the present invention includes a flexible portion and a highly rigid portion that are superposed on each other, and the density of the flexible portion is higher than 80 kg / m ³ and not higher than 100 kg / m ^3. Provided is a glass fiber heat-absorbing sound absorber characterized in that the density of the rigid portion is 120 kg / m ³ to 300 kg / m ³ and the flexural modulus is 150 MPa to 500 MPa.

Preferably, the flexible portion has a thickness of 20 mm to 30 mm, and the high rigidity portion has a thickness of 3 mm to 10 mm.

Preferably, the glass fiber forming the high-rigidity part has a fiber diameter of 7 μm or more, and the density of the high-rigidity part is 120 kg / m ³ to 150 kg / m ³ .

Further, in the present invention, the glass is characterized in that the high-rigidity part is attached to an automobile engine in a state where a part or all of the high-rigidity part is exposed so that the high-rigidity part is outside the glass fiber heat-absorbing sound absorber. Provided is a method for using a fiber heat-absorbing sound absorber.

According to the present invention, since the flexible portion and the high-rigidity portion are overlapped, the chipping performance and the like can be exhibited by the high-rigidity portion while exhibiting a sound absorbing effect by the flexible portion. Moreover, weight reduction can be achieved by forming both with glass fiber. In particular, the weight can be drastically reduced as compared to using a metal molded product or a thermoplastic resin molded product as the high-rigidity portion. That is, the sound absorbing effect can be exhibited while having a rigidity sufficient to prevent damage by chipping, and further weight reduction can be achieved. In addition, the density of the flexible part is higher than 80 kg / m ³ and 100 kg / m ³ or less, and the density of the high-rigidity part is 120 kg / m ³ to 300 kg / m ³ , so that resonance in the vicinity of 3000 Hz to 4000 Hz is achieved. It has been confirmed that it is possible to prevent a decrease in sound absorption coefficient due to the phenomenon. For this reason, it is suitable for preventing a partial decrease in the sound absorption coefficient in a wide frequency band emitted by an automobile engine.

In addition, by making the thickness of the flexible portion 20 mm to 30 mm and the thickness of the high rigidity portion 3 mm to 10 mm, it is possible to achieve an optimum weight reduction. That is, within this thickness range, it is possible to achieve optimum sound absorption performance and light weight in combination with the density and elastic modulus of the flexible portion and the high rigidity portion, and to obtain a thickness that is easy to handle.

Further, if the fiber diameter of the glass fiber forming the highly rigid portion is 7 μm or more, the density of the highly rigid portion can be lowered. Thereby, the sound absorption effect to some extent by a highly rigid part can be exhibited, maintaining the rigidity which can implement | achieve chipping-proof property.

In addition, with a part or all of the high-rigidity part exposed, it is attached to the automobile engine so that the high-rigidity part is outside the glass fiber heat-absorbing sound absorber. Since it has a natural part, the sound absorption effect can be fully exerted, and when mounted on the underside of an automobile engine, a high-rigidity part is arranged on the side that receives chipping, so chipping performance is also improved. Can fully demonstrate. Further, it is possible to prevent a decrease in sound absorption coefficient due to a resonance phenomenon in the vicinity of 3000 Hz to 4000 Hz in a wide frequency band emitted by the engine.

It is the schematic of the glass fiber heat insulation sound absorber which concerns on this invention. It is the graph which compared the sound absorption rate of Example 1 and a comparative example. It is a table | surface which shows the result of having compared the sound absorption rate of Example 1 and 2 and a comparative example. It is a graph which shows a resonance phenomenon.

As shown in FIG. 1, a glass fiber heat-absorbing sound absorber 1 according to the present invention includes a flexible portion 2 and a high-rigidity portion 3. The flexible portion 2 and the high-rigidity portion 3 are obtained by pressure-heating molding a mat-like glass fiber assembly (hereinafter referred to as an intermediate) to which an uncured thermosetting binder is attached.

Although there are many types of glass fibers, there is no particular limitation on the glass composition of the glass fibers used in the present invention, but a soda lime glass used for glass wool insulation or a glass composition called A glass is preferred. . If it is the said glass composition, it is excellent in economical efficiency at the point that mass production is possible by using a centrifugal method at a comparatively low melting temperature.

The fiber diameter of the glass fiber is not particularly limited, but the fiber diameter is preferably in the range of 3 μm to 10 μm. If the fiber diameter is in the above range, the object of the present invention can be satisfied even if it is used for a flexible part or a high-rigidity part, and glass fibers having the same fiber diameter are used for the flexible part and the high-rigidity part. Or you may use the glass fiber from which a fiber diameter differs in a flexible part and a highly rigid part.

Further, the glass fiber used for the flexible part preferably has a fiber diameter of 3 μm to 7 μm, and more preferably a fiber diameter of 3 μm to 5 μm. In a glass fiber heat-absorbing sound absorber, even if the density of the sound absorber is the same, if the fiber diameter of the constituting glass fiber is reduced, the number of glass fibers per unit volume increases, and as a result, the glass fibers cross each other. The space formed is small and the number is large, so that sound absorption is improved. Even in the flexible part of the glass fiber heat-absorbing sound absorber of the present invention, it becomes easy to achieve the object of the present invention by using glass fibers having a fiber diameter in the above range.

The glass fiber used for the high-rigidity part preferably has a fiber diameter of 4 μm to 10 μm, and more preferably 7 μm to 10 μm. When the glass fiber diameter is in this range, the flexural modulus is increased without increasing the density of the glass fiber heat-absorbing sound absorber.

The uncured thermosetting binder used in the present invention is preferably an aqueous aldehyde condensable resin. Examples of the aldehyde condensable resin include a resol type phenol resin, an amino resin, and a furan resin.

The phenol resin is a resin obtained by an addition reaction between phenols and aldehydes. Examples of the phenols include phenol, cresol, xylenol, resorcin, and modified products thereof. Examples of the aldehydes include formaldehyde, Examples include acetaldehyde, furfural and paraformaldehyde.

The amino resin is a resin obtained by an addition reaction of urea and a compound having an amino group derived from urea such as melamine, acetoguanamine, benzoguanamine and aldehydes. In a similar manner, a resin obtained by an addition reaction between a compound having an amino group such as polyacrylamide, amino alcohol, or polyamine and an aldehyde can also be used.

When an aldehyde condensable resin is used, each resin may be used alone, or the above resins may be mixed and used. For example, a part of the phenol resin may be replaced with a melamine resin or a urea resin.

The thermosetting binder used in the present invention neutralizes a pH adjuster, a curing accelerator, a silane coupling agent, a colorant, a dustproof agent, and an alkali component eluted from inorganic fibers in addition to the main component thermosetting resin. An additive such as a neutralizing agent may be added as necessary. The binder is adjusted to a predetermined concentration by mixing the above components according to a conventional method and adding water.

The adhesion amount of the uncured thermosetting binder in the mat-like glass fiber aggregate (intermediate) is preferably 5% by mass to 20% by mass with respect to the total mass of the glass fiber aggregate. .

Further, in the mat-like glass fiber assembly (intermediate body) used for forming the flexible portion, the adhesion amount of the uncured thermosetting binder is preferably 5% by mass to 15% by mass. . If the adhesion amount of the uncured thermosetting binder is within the above range, the requirements regarding the density and (elastic modulus) of the flexible part of the present invention can be satisfied.

When the adhesion amount of the uncured thermosetting binder is less than 5% by mass, the density of the flexible part after molding may not exceed 80 kg / m ^{3. When} the adhesion amount exceeds 15% by mass, the flexibility is increased. The density of the part may exceed 100 kg / m ³ , and both the sound absorption properties of the flexible part are lowered.

On the other hand, in the mat-like glass fiber assembly (intermediate body) used for forming the high-rigidity part, the adhesion amount of the uncured thermosetting binder is preferably 10% by mass to 20% by mass. . If the adhesion amount of the uncured thermosetting binder is in the above range, it becomes possible to reach the density and bending elastic modulus of the high-rigidity part intended by the present invention. When the adhesion amount of the uncured thermosetting binder is less than 10% by mass, the density and bending elastic modulus of the high-rigidity part after molding may not be in the desired range, and when the adhesion amount exceeds 20% by mass, The density and bending elastic modulus of the high-rigidity portion are not improved further, which is uneconomical.

The glass fiber heat-absorbing sound absorber 1 is formed by overlapping the flexible portion 2 and the highly rigid portion 3 with each other.

Here, the density of the flexible portion 2 is higher than 80 kg / m ³ and not higher than 100 kg / m ³ . When the density of the flexible portion is higher than 80 kg / m ³ , the sound transmitted through the sound absorber is reduced and the sound absorption rate is improved. On the other hand, by setting the density of the flexible portion to 100 kg / m ³ or less, reflection of sound due to an increase in sound absorber density is suppressed, and the sound absorption rate is improved. That is, the density at which the optimum sound absorption coefficient can be obtained is higher than 80 kg / m ³ and not higher than 100 kg / m ³ .

The thickness of the flexible part 2 is 15 mm to 30 mm, preferably 20 mm to 30 mm. When the thickness of the flexible portion is 15 mm or more, the sound that is transmitted decreases, and the sound absorbing performance becomes sufficient. On the other hand, when the thickness of the flexible portion is 30 mm or less, a sound absorbing body that can be installed in a narrow space such as an engine room of an automobile while maintaining sound absorbing performance is obtained.

On the other hand, the density of the high rigidity portion 3 is 120 kg / m ³ to 300 kg / m ³ . If the density of the high-rigidity part 3 is 120 kg / m ³ or more, rigidity having chipping resistance can be obtained, and if it is 300 kg / m ³ or less, it is possible to suppress a decrease in sound absorption performance due to sound reflection. it can. From the viewpoint of sound absorption performance, the density of the highly rigid portion 3 is more preferably 250 kg / m ³ or less.

Also, the flexural modulus of the high rigidity portion 3 is 150 MPa to 500 MPa, more preferably 180 MPa to 300 MPa. When the flexural modulus of the high-rigidity portion is 150 MPa or more, handleability of the sound absorber during installation in the automobile engine room is improved and chipping resistance is provided. If the flexural modulus of the high-rigidity part is 500 MPa or less, the phenomenon that the rigidity becomes too high and the reflection of sound increases can be avoided.

The thickness of the highly rigid portion 3 is 3 mm to 10 mm, preferably 5 mm to 8 mm, and most preferably 5 mm. However, the thickness is appropriately set in consideration of optimizing the weight and rigidity of the sound absorber 1. If the thickness of the highly rigid portion is 3 mm or more, the handleability and chipping resistance of the sound absorber are improved, and if the thickness is 10 mm or less, an increase in the mass of the sound absorber can be suppressed.

By making the flexible portion 2 and the high-rigidity portion 3 have such characteristics, the high-rigidity portion 3 is imparted with a certain level of sound-absorbing performance and rigidity while giving the flexible portion 2 highly effective sound-absorbing performance. be able to. Therefore, the sound absorber 1 can have high sound absorption performance and also has chipping resistance.

As described above, since the sound absorber 1 has the flexible portion 2 and the high-rigidity portion 3 overlapped with each other, the high-rigidity portion 3 can exhibit chipping resistance while exhibiting a sound-absorbing effect. . Moreover, weight reduction can be achieved by forming both with glass fiber. In particular, the weight can be drastically reduced as compared with the case where a metal plate or a resin plate is used as the high-rigidity portion 3. That is, the sound absorbing body 1 can exhibit a sound absorbing effect while having rigidity sufficient to prevent damage by chipping, and can further reduce the weight.

Further, 150 MPa higher than 80 kg / ^{m 3} density flexible portion 2 and 100 kg / ^{m 3} or less, a density of ^{120kg / m 3 ~ 300kg / m} 3 and a flexural modulus of rigidity area 3 of the high-rigidity area It has been confirmed that by setting the pressure to ˜500 MPa, it is possible to prevent a decrease in sound absorption coefficient due to a resonance phenomenon in the vicinity of 3000 Hz to 4000 Hz. For this reason, the sound absorber 1 is suitable for preventing a partial decrease in sound absorption coefficient in a wide frequency band emitted by an automobile engine.

When the fiber diameter of the glass fiber forming the high rigidity portion 3 is 7 μm or more, the density of the high rigidity portion is preferably 120 kg / m ³ to 150 kg / m ³ . Thus, if the fiber diameter of the glass fiber forming the highly rigid portion 3 is 7 μm or more, the density of the highly rigid portion 3 can be lowered. Thereby, the sound absorption effect to some extent by the high-rigidity portion 3 can be exhibited while maintaining the rigidity that can realize chipping resistance. That is, if the fiber diameter is 7 μm or more, a high elastic modulus can be obtained without increasing the density of the high-rigidity portion 3, which is preferable in terms of weight reduction and economy.

There is no particular limitation on the molding method of the glass fiber heat-absorbing sound absorber of the present invention, but preferred molding methods are as follows.

(1) First, a highly rigid portion is formed.
The mold to be used has a gap that matches the size of the highly rigid portion. An intermediate body with a mass calculated from the desired density and dimensions as a highly rigid part is placed in the mold and cured at a pressure of 8 Tpa to 12 TPa and a temperature of 200 ° C. to 250 ° C. for 1 minute to 5 minutes. Mold the part.

(2) Next, the flexible part is formed on the highly rigid part.
The mold to be used has a gap having a dimension obtained by adding the dimension of the flexible part to the dimension of the heat insulating sound absorber of glass fiber, that is, the dimension of the highly rigid part. The previously molded high-rigidity part is placed in the mold, and an intermediate body having a mass calculated from the desired density and dimensions of the flexible part is placed in the mold, and the pressure is 8 TPa to 12 TPa, the temperature Curing is performed at 200 ° C. to 250 ° C. for 1 minute to 5 minutes to form a sound absorber.

The high-rigidity part and the flexible part are bonded together by an uncured thermosetting binder contained in the intermediate body when the flexible part is molded. If it is said molding conditions, adhesion of a highly rigid part and a flexible part is enough.

(Example 1)
As Example 1, the following glass fiber heat insulating sound absorber was obtained. First, the molten glass was made into glass fibers having an average fiber diameter of 4 μm by a centrifugal method, and immediately after that, an aqueous binder made of a resol type phenol resin was sprayed. The adhesion amount of the aqueous binder was 13% by mass to obtain an intermediate. The intermediate is cut to a weight of 250 g and placed in a mold having a 500 mm square and a depth of 5 mm, and heated and pressed at a mold temperature of 240 ° C. and a molding pressure of 10 TPa for a molding time of 2 minutes. Cured. As a result, a high-rigidity portion having a 500 mm square, a thickness of 5 mm, a density of 200 kg / m ³ , and a (bending) elastic modulus of 250 MPa was obtained. On the other hand, this high-rigidity part is installed in a mold having a gap of 30 mm and a depth of 500 mm, and the intermediate body is cut so as to have a mass of 506 g and stacked with the high-rigidity part to obtain a mold temperature. It was cured by heating and pressing at 240 ° C. and a molding pressure of 10 TPa for a molding time of 5 minutes. Thereby, the glass fiber heat-insulating sound absorber of Example 1 was molded. In addition, the part laminated | stacked on the highly rigid part was a flexible part, and this flexible part was thickness 25mm and density 81kg / m < ³ >.

(Example 2)
As Example 2, the following glass fiber heat-absorbing sound absorber was also obtained. First, melted glass was made into glass fibers having an average fiber diameter of 7 μm by a centrifugal method, and immediately thereafter, an aqueous binder made of a resol type phenol resin was sprayed. The adhesion amount of the aqueous binder was set to 10% by mass to obtain such an intermediate. The intermediate body is cut to a mass of 160 g, placed in a mold having a 500 mm square and a gap of 5 mm depth, and heated and pressed at a mold temperature of 240 ° C. and a molding pressure of 10 TPa for a molding time of 1 minute. Cured.

As a result, a highly rigid portion having a thickness of 5 mm, a density of 128 kg / m ³ , and a (bending) elastic modulus of 200 MPa was obtained. On the other hand, this high-rigidity part is installed in a mold having a gap of 25 mm in depth of 500 mm square, and the intermediate body is cut so as to have a mass of 405 g and laminated with the high-rigidity part to obtain a mold temperature. It was cured by heating and pressure at 240 ° C. and a molding pressure of 10 TPa for a molding time of 4 minutes. In this way, the glass fiber heat insulating sound absorber of Example 2 was molded. In addition, the part laminated | stacked on the highly rigid part was a flexible part, and this flexible part was thickness 20mm and density 81kg / m < ³ >.

(Comparative example)
As a comparative example, the following glass fiber heat insulating sound absorber was obtained. The above-mentioned intermediate is cut to a mass of 750 g, placed in a mold having a gap of 30 mm and a depth of 500 mm, a molding temperature of 240 ° C., a molding pressure of 10 TPa, and a molding time of 7.5. Heat and pressure curing in minutes. This obtained the glass-fiber heat-insulation body of the comparative example of thickness 30mm, density 100kg / m < ³ >, and (flexural) elastic modulus 84MPa.

As shown in FIG. 2, when the sound absorptivity with respect to the sound frequency of Example 1 and the comparative example was measured, a resonance phenomenon was observed around 3150 Hz in the comparative example (solid line B in FIG. 2), and the sound absorptivity decreased. Was confirmed. On the other hand, in Example 1 (solid line C in FIG. 2), no decrease in sound absorption was observed at 3000 Hz to 4000 Hz where the resonance phenomenon was observed. This is an effect obtained by combining the density and elastic modulus of the flexible portion and the high rigidity portion.

As shown in FIG. 3, the (normal incidence) sound absorptivity was measured at predetermined frequencies for Examples 1 and 2 and the comparative example. The measurement was performed according to JIS A-1405-2. In both Examples 1 and 2, the sound absorption rate was higher at any frequency compared to the comparative example. Also in Examples 1 and 2, no resonance phenomenon has been confirmed.

The above-described glass fiber heat-absorbing sound absorber 1 is used by being attached to the lower part of the engine room of an automobile with a part or all of the high-rigidity part 3 exposed. According to such a method of use, since the flexible portion 2 is arranged on the engine side serving as a sound source, the sound absorbing effect can be sufficiently exerted, and the high-rigidity portion 3 is arranged on the side receiving the chipping. Therefore, the chipping resistance can be sufficiently exhibited. Further, it is possible to prevent a decrease in sound absorption coefficient due to a resonance phenomenon in the vicinity of 3000 Hz to 4000 Hz in a wide frequency band emitted by the engine.

1: Glass fiber heat-absorbing sound absorber, 2: Flexible part, 3: High-rigidity part

Claims (4)

A flexible portion and a high-rigidity portion that are formed by entwining a plurality of glass fibers and overlapped with each other,
The density of the flexible portion is higher than 80 kg / m ³ and not higher than 100 kg / m ³ ,
The glass fiber heat-absorbing sound absorber, wherein the high-rigidity portion has a density of 120 kg / m ³ to 300 kg / m ³ and a flexural modulus of 150 MPa to 500 MPa. 2. The heat insulating sound absorber for glass fiber according to claim 1, wherein the thickness of the flexible portion is 20 mm to 30 mm, and the thickness of the highly rigid portion is 3 mm to 10 mm. The fiber diameter of the glass fiber forming the high-rigidity portion is 7 μm or more, and the density of the high-rigidity portion is 120 kg / m ³ to 150 kg / m ³ . Glass fiber insulation sound absorber. 4. The method according to claim 1, wherein the high-rigidity part is attached to an automobile engine in a state in which a part or all of the high-rigidity part is exposed so that the high-rigidity part is located outside the glass fiber heat-absorbing sound absorber. A method of using a glass fiber heat-absorbing sound absorber using the glass fiber heat-absorbing sound absorber.

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